Diana Nguyen said her keys were taken from her unlocked locker at the gym on Adams Street, and the remote device was then used to locate her car.

The suspect, identified by Quincy Police as Aimee L. Elder, 21, is charged with stealing Nguyen's purse from her car.

Police said Nguyen used the GPS on the phone in the purse to track it to a nearby Starbucks, where the phone was found in a dumpster behind the store.

A photo Nguyen had obtained from surveillance video taken at the gym allowed employees at Starbucks to identify Elder as a customer. When Elder returned to Starbucks the next day, employees called police, who arrested her.

Police said Elder, who still had Nguyen's purse, was charged with larceny, and breaking and entering.

A maid who cleaned the home of former New England Patriots player Aaron Hernandez has testified at his murder trial that she saw him "messing with" the security camera in his basement the day after the killing.